Question

How to find the indexes of the first and last occurrences of an element in array in TypeScript

Answer 1

function findFirstAndLastIndex(array: number[], element: number) {
    let first: number = -1, last: number = -1;
    const size: number = array.length;
     
    for (let i: number = 0; i < size; i++) {
        if (array[i] != element) {
            continue;
        }
         
        if (first == -1) {
            first = i;
        }
         
        last = i;
    }
     
    if (first != -1) {
        console.log("First Occurrence = " + first);
        console.log("Last Occurrence = " + last);
    }
    else {
        console.log("Not Found");
    }
}
         
const array: number[] = [3, 2, 4, 7, 3, 0, 9, 8, 7, 7, 12, 18];
let element: number = 7;
         
findFirstAndLastIndex(array, element);
 
 
 
 
/*
run:
 
"First Occurrence = 3" 
"Last Occurrence = 9" 
 
*/

 

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